As indicated in FIG. 1 and FIG. 2, in a conventional four-section umbrella strut spreader structure, the U-shaped opening in the umbrella strut member (a) near the center pole faces downward. When the user opens or closes the umbrella strut spreaders during operation, the hands are easily injured by the umbrella strut member (a) if caution is not exercised. Furthermore, there is a sleeve (d) that directly conjoins the leaf-type strut member (b) to the third main strut member (c) (as indicated in FIG. 2) and the leaf-type strut member (b) is positioned at a relatively greater distance from the third main strut member (c) at the base (cl) of the sleeve (d), which results in difficult operation when the umbrella is opened and folded as well as frequent malfunctions.
In view of the aforementioned shortcomings, the primary objective of the invention herein is to overcome the disadvantages of conventional four-section umbrella strut spreader structures to offer a safe and smoothly operating four-section umbrella strut spreader structure. The innovations and functions of the invention herein are elaborated in the attached drawings and detailed description.